There is provided a distance measuring apparatus in a lens-shutter type camera provided with a photographic lens, a focal length of the photographic lens being variable. The distance measuring device includes: a pair of image forming lenses each forming a subject image; a pair of line sensors on which the subject images are respectively formed through the pair of image forming lenses, the pair of linesensors each having a plurality of light receiving elements; a plurality of light receiving areas formed correspondingly on each of the pair of line sensors, the plurality of light receiving areas each including a predetermined number of the plurality of light receivingelements, wherein the plurality of light receiving areas respectively receive different areas of a corresponding one of the subject images formed through the pair of image forming lenses, and wherein each adjacent pair of light receiving areas of the plurality of light receiving areas overlap each other; means for detecting a current focal length of the photographic lens; and means for shifting at least one of the plurality of light receiving areas on each of the pair of line sensors in accordance with the currentfocal length detected by the detecting means, wherein each light receiving element included in the at least one of the plurality of light receiving areas shifted by the shifting means is used to convert received light into an electrical signal which is integrated to output image data.